tools: enforce function name matching in linter

ESLint has a `func-name-matching` rule that requires that function names
match the variable or property to which they are being assigned.

The code base currently has 100% compliance with this rule.

Enable the rule to keep it that way.

PR-URL: https://github.com/nodejs/node/pull/9408


Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: Prince John Wesley <princejohnwesley@gmail.com>